Plugging Energy Regeneration Improves Braking Torque at Low Speed Instead of Dynamic Energy Regeneration.

Previously, we proposed a dynamic energy regeneration used in robotic prostheses. However, a dynamic energy regeneration cannot provide enough torque at low speeds and for a robotic prostheses, low torque may result in falling down in some cases. In this study, we proposed a plugging electrical energy regeneration instead of dynamic electrical energy regeneration, which can provide relatively larger torque at low speeds. Firstly, the mathematical model and formula of a dynamic energy regeneration and a plugging energy regeneration were given. Theoretically, for a plugging energy regeneration, due to the current drain from the power supply, the braking current is larger than the current for a dynamic energy regeneration, at the same low speed, indicating more braking torque. Further, we designed a drive circuit of energy regeneration, to verify two methods of a dynamic energy regeneration and a plugging energy regeneration. Experiment results showed that at low speeds, the braking torque is larger using a plugging energy regeneration than the torque using a dynamic energy regeneration, in accordance with the results from the mathematical model. From the mathematical model and physical experiments, this study showed the potential of a plugging energy regeneration used in a robotic prosthesis, to deal with the weak braking torque at low speeds.